Water-in-oil soluble oil



Nov. 30, w54 c. vv. NICHOLS, JR., ET AL wATER-IN-OIL soLUBLr: OIL

Filed March l. 1950 Sm SSMQ um w w m Q w w W Se United States Patent Gtice 2,695,877 Patented Nov. 30, 1954 WATER-IN-on. soLUBLE OIL Clayton W. Nichols, Jr., Mineola, and Harold J. Schroeder, Brooklyn, N. Y., assignors to Socony-Vacuum Oil Company, Incorporated, a corporation of New York Application March 1, 1950, Serial No. 146,948

4 Claims. (Cl. 252-37.2)

The present invention relates to soluble oils and, more particularly, to soluble oils suitable for use both as lubricant and coolant in the rolling of metal.

It has long been the goal of lubricant manufacturers to supply to the metal rolling mills a lubricant which likewise had the desirable physical characteristics of a coolant. Such a lubricant would satisfy a need in the metal rolling industry for at least two reasons. First, when an oil is used for lubrication and water is used as a coolant, the two inevitably at some time mix through leaks in one system or the other, through carelessness or because of some other unavoidable cause. Secondly, there is at least one high speed mill which because of design requires that the lubricant be the coolant.

When approaching this problem it must be remembered that the efliciency of a coolant is dependent upon its specific heat; i. e., the amount of heat energy required to raise the temperature of a unit weight of the material one degree at temperatures below the vaporization temperature. While mineral oil is an excellent lubricant, it is a poor coolant as compared to water because the specific heat of mineral oil is only about 0.5 that of water. On the other hand, it is well-known that except under special conditions water is not a good lubricant. Thus, the art has been confronted with this problem ever since the inception of metal rolling and particularly since the development of high speed rolling.

It is axiomatic that the reduction in thickness of a piece of metal is accompanied by the generation of heat. It is also manifest that the heat so generated must be dissipated by some means. Under many conditions the heat so generated can be absorbed by water but in other circumstances such is not possible.

In recent years high speed rolling of accurately sized strip has been achieved in the Sendzimir mill. However, this mill requires that the lubricant also be the coolant. Consequently, the Sendzimir mill typies the problem confronting the manufacturer of lubricants.

The solution of the problem of providing a coolantlubricant for use under conditions such as are typified by the Sendzimir mill is not solely dependent upon providing a lubricant with a specific heat approaching as closely as possible that of water. It is also necessary to provide a material having a Viscosity suitable for the use to which it is t be put. In other words, a satisfactory coolant-lubricant must have a controlled Viscosity.

Several coolant-lubricants have been offered to the metal rolling industry but have been unsatisfactory for one reason or another. Thus, for example, many emulsions have failed to be satisfactory because the viscosities thereof were too low.

It has now been discovered that a satisfactory coolantlubricant having a controlled viscosity and a specific heat appreciably greater than that of mineral lubricating oil can be produced.

It is an object of the present invention to provide a coolant-lubricant having a controlled viscosity.

It is another object of the present invention to provide a coolant-lubricant having a controlledv viscosity between about 100 Saybolt Seconds Universal and about 11,000 Saybolt Seconds Universal at 100 F.

It is a further object of the present invention to provide a coolant-lubricant comprising a lubricating fraction of mineral oil, water, a primary emulsier and a'secondary emulsiiier. l

Other objects and advantages will become apparent from the following description:

The heat-absorbing capacity of the novel, controlledviscosity, coolant-lubricant is approximately 50 per cent greater than that of mineral oil and a 50 per cent water emulsion has a specific heat of 0.74. The stability of the novel, controlled-viscosity, coolant-lubricant is excellent even at pressures of 5,000 pounds per square inch. The evaporation of water from the novel, controlledviscosity, coolant-lubricant is at a much lower rate than the evaporation of water from prior art conventional soluble oil emulsions of the oil-in-water type. Emulsions of the base stock and water are readily formed without the use of special equipment such as colloid mills, homogenizers and the like.

The base stock of the coolant-lubricant comprises a major proportion of mineral oil. Since the viscosity of the coolant-lubricant is to some extent dependent upon the viscosity of the fraction of mineral oil employed, the mineral oil shall have a viscosity of about 40 to about 900 Saybolt Seconds Universal at F. In addition to the mineral oil, the base stock comprises a minor proportion of one or more anti-wear and anti-rust agents, a minor proportion of one or more film-strength improvers, a controlled amount of one or more primary (water-in-oil) emulsiiiers and a controlled amount of one or more secondary (oil-in-water) emulsifiers.

For example, a base stock can be compounded in accordance with the following formulation:

Percent Ingredient Function by Weight Neutral Degras Anti-wear and anti-rust-.. 5, 0 Di (glycolmono-oleate) malate.. o 1.0 Oleyl acid phosphate Film strength improver..- 0.5 Cllirinated hydrocarbon (42% do 2. 5 Aluminum Stearate Primary Emulsitler 1. 5 Fatty acid ester of a hoxitol ando 2. 0

hydride, said fatty acid having at least 6 carbon atoms. Polyoxyalkylene derivative of a Secondary Emulsier 2.0

fatty acid ester of a hexitol anhydride, said fatty acid having at least 6 carbon atoms. 100" Palo Parafn Oil 85.5

23.9. 157 seconds.

Characteristics of 50% emulsion with water of the afore described base stock Specific Heat 0.74.

S. U. Viscosity at 100 F 600 seconds.

Emulsion Stability Slight oil separation in two Weeks.

Base Oil 42/45 Pale Parafn Oil.

Oleic Acid Primary Emulsitler l (Wate Secondary Emulsier 2 (Oil-in-Water) 1 For example, 1-hydroxyethyl-2-heptadecenyl glyoxalidine (Amine 220 2 For example, polyoxyalkylene derivative described in column 2.

As` ha's`be'n' emphasized hereinbefore, the viscosity of the uwater Yemulsion prepareds'from' the Inovel "base ustock can be controlled within the limits of about 100 to about 11,000 seconds Saybolt Universal at 100 F. That is to say, the concentration of the secondary emulsiiier controls the viscosity of the'emulsion prepared from the harge stock. This is clearly illustrated by the following ata:v

1 Containing 2% of secondary emulsier.

2 1-hydroxyethyl-2-heptacedenylglyoxalidine.

3 Containing 0.8 primary emulsilier.

4 Polyoxyalkylene derivative described in column 2.

Those skilled in the art will recognize that the fore'- going blends of base oil A with 0.9 per cent to 2.5 per f cent primary emulsifier and of base oil B with 1.5 per cent' to 2.5 per cent secondaryemulsier provide emulsifiable oils containing, when base oil A is used, about '0.9 per cent-about 2.5 per cent primary emulsifler,'about 2 per cent secondary emulsifier, about 5 per cent oleic r acid and the balance mineral oil and, when base oil B is employed, about 0.8 per cent primary emulsier, about 1.5 percent to about 2.5 per cent secondary emulsier, about 5 per cent oleic acid and the balance mineral oil. Therefore it is general about 0.8 per cent to about 2.5 per cent primary emulsifier, about 1.5 per cent to about 2.5 per cent secondary emulsier, about 5 per cent oleic acid and the balance mineral oil, the concentration of secondary emulsiierwbeingcontrolled to produce a soluble Voilblend capable when'diluted of providing a lubricant coolant of controlled viscosity. g

The soluble oils (base oils) when emulsied with an equal amount of'water have lubricating properties'.y approaching those of lubricating oils. lished by wear tests in heavily loaded anti-friction bearings and in Vickers vane type pumps.

The anti-rust properties of 50 per cent emulsions of these base oils are markedly superior to those of the manifest that these blends contain in This has been estabconventional soluble oil emulsions of the oil-in-water type.

In fact, the rust preventive properties of such emulsions areV classified as good.

The stability of 50 per cent emulsions of these novel base'oils-is excellent even at pressures-of 5,000 pounds per square inch (p. s. i.) under very close clearance conditions as in bearings or high pressurepumps. Although very slight' amounts of oil may separate as a cuff after ytheemulsions remain in a quiescent state for Vseveral weeks, it is readily re-emulsied when the oil is simply agitated. This is in contrast to the diiculty encountered when attempting to Vre-emulsify conventional oil-in-water emulsions.

Whereas the viscosity of conventional oil-in-'water emulsionscannot be controlled by soluble oil, i. e., base oil, composition, the viscosity of the emulsions of the present novel base oils can be controlled over a broad range by modification of the formulation of the base oil as' demonstrated hereinbefore and/ or the viscosityof the mineral oil base.

The lubrication properties of the novel soluble-oil emulsions were determined in comparison with several prior art soluble oils and a straight mineral lubricating oil available to the trade.

SKF double row, tapered roller bearings were run at 100 per centrated load (860 pounds) at 1750 R. P. M. for 400 hours in the S. G. O. L. test machine described hereinafter. Under these test conditions soluble oils'A, B `and' C failed rapidly, whereas the novel soluble oils gave excellent results. A conventional lubricating oil was also tested. While the conventional lubricating oil provides satisfactory lubrication, it is unsatisfactory for use in high speed mills such as the Sendzimir mills Vbecause of its inability to carry away efficiently the heat generated'fduring'fthe rolling operation.' Consequently,

4.-. non-uniform sheets result. Conventional soluble oils dissipate` hthe` heat; butfrequentrbeang failuresoccuras has been demonstrated by these tests.

The SGOL machine is esentially a vertically loaded horizontal shaft which in turn rests on two replaceable roller bearings which are supplied with the lubricant under test. Lubricant performance characteristics are evaluated by roller bearing weight loss and by bearing appearance at the termination .of a test run.

Two weighted lever varnrs'rest on heavy duty roller bearings situated near-fthe middleofwthefshaft. In the present testsa new rollei bearing assembly was used withfeach test lubricant; The lubricants '.were evaluated at arload of860v pounds per .bearingu'aud` a shaftvspeed of 17'50 R. P. Onegallomof ytest lubricant kWas-` used for each bearing and the lubricant was circulated from a lubricant lasumpfzbyfmeans `of a Ypositive" displacement rotary pump.

Inspection of =bearing=iraees forsp'alling, pitting, rusting and similar visually determined evidence of the satisfactory or unsatisfactory properties of the test lubricantsvwas also madei'- The conditions `andfresults oftheaforedescribed'fcomparative tests are presented in Tble If Cgifentional' Lubricating Excellent', no spalling.'

Soluble 011A. 1 :6 VSlight-,spelling ofrollers.l Soluble Oi .lB 1:6 Spalling on outer race. Soluble Oil'C 1 :6 Several spelling' on f both l rollers andtouter race. l Novel solubleoil 1:1 Ex'llenbyno spelling; f

It will `be*notedtl1atfthel lubricating 'properties ofthe .novel solubleoil are'comparabl'e to'th'sefoflubrlcating'oil.

To furtherte`st 'th'e lubricating4 properties of lthe' novel solubleoils an'dfto test' thef'stabilityfofthe-emulsions made therefrom underi'high ipressures', 'fth' novel vsoluble oils weresubjected to the V ickers 'Hydraulici'Piimp Test describedinLubrication Engineering, J. A. S,.-"L."E.',vol."5, No; 1, February1949,l pages-16 fand- 17."1

Briefly, the test' `equipment 'and 'tha/conditions 'of the test` `are as Afollows :i

The unit consists offalvane `type-pump,`drectly icon'- nected to a 3H; P electric'motdrs The"oi1='es'ervoir is mounted on the sametable with"'th-motorj"andpump, and the vvoil fstraineris attached tothe oil intake 'line inl the' reservoir. Operating pressure 'is-controlled' by 'a relief valve whichfis fitted into the pressure line from the pump. The oil at lowpressure returns tolthereservoir through'a flow"meter. Operating y.temperatures vofthe hydraulic fluid areffcontrolled `by means'of 'anrautomatic electrothermo regulatorand a Water cooling 'co'il.`f.

The standard procedure for conducting `arurrinvolv'es circulating the oil at'a temperature of`175`` F. under a pump pressure of 1000 p. s. i. for-a period 'of '1000 hours. In beginning the test,'-the lmachineis completely/'disassembled and all partsand lines .arethoroughly cleaned. A completeset of' new-`pumpfparts;i.Je.; rotor, ring, bronze'bushings andv weighdiyane's', is'instailled and Vthe system is thoroughly flushedwithnew heated oil." The unit is given a break-in run whichiscontinued until a steady flow rate yof about `ligalloris perminuteis attained. After draining the break-in charge," three gallons of test oil are thenintroduced into the-system ,and .the test is started. A two ounce sample of the'oil lis'removed at intervals` of hoursforphysieal.and chemicaltests, and the pumpisopened `for `inspection..every/250 hours. At the completion'of the-run, the vanes are' againweighed to vdetermine metal lossdu'e to-twearxl Thepump fparts and the entire systenrvare` linspected iforwevidencefof corrosion and the presenceof deposits;

The results of'te'sting aflightlubricatingwoil,"a conventional: soluble oil-tand 'afnov'el s'olublef oilfare ypresented in Table II.

TABLE II Temper- Vane Ring Flow Product Presssur" ature, Emfs Wear, Wear, Rate,

p F. Percent Percent G. P. M.

Light Lube O11 1, 000 175 1, 000 3. 15 3. 3 1. 4 500 130 109 0. 89 0. 01 0. 35 Prior A rt Soluble Oil. 200 130 1, 000 1. 6 0.04 1. 8 (1)140 (liso (1)0 2 (ifi 4 (l) 2 4 Novel Soluble OH 1,000 170 185 1I 5 0141 2 2 1 Pump inoperable at this pressure.

The data presented in Table II establish that the novel soluble oil approaches light lube oil in anti-wear properties and is superior to conventional prior art soluble oils.

The novel soluble oils were subjected to the wellknown Falex wear test in comparison with a light lubricating oil and prior art soluble oils. The data thus obtained are presented in Table III.

TABLE III Falex wear test-Steel pins and steel bushings at 290 R. P. M.

15 minute break-in period ag 50 pounds load. 60 minute wear period at 200 pounds load.

It is apparent after consideration of the foregoing data that the novel soluble oil containing 100l mineral oil and anti-wear and film-strength additives is substantially equivalent in 1:1 emulsion to light lubricating oil. It is also apparent that the novel soluble oil is far superior to the prior art soluble oils A and B at the same concentration; i. e., 1:1 emulsion. It will also be noted that at higher dilutions; i. e., 1:6 of the prior art soluble oils some improvement is attained. However, it is likely r that this improvement is due to the greater cooling effect at the higher dilution.

The specific heat, and consequently the ability to cool, varies linearly with the concentration of water in the emulsion. Thus, the mineral oil from which the novel soluble oils were prepared had a specific heat of 0.48; a 1:1 emulsion of the novel soluble oil had a specific heat of 0.74; an emulsion containing 85 per cent water had a specific heat of 0.935i0-015.

The control of the viscosity of water-in-oil emulsions of the novel soluble oils can be exercised in three ways. The simplest method is by controlling the amount of water. The maximum amount of water which can be added to or emulsied in the novel soluble oils is slightly less than 70 per cent. When 70 per cent or more water is added to the novel soluble oils, the emulsion breaks and separates into two or more phases.

A second means of controlling the viscosity of waterin-oil emulsions is by using base oils of greater or less viscosity. On the other hand, increasing the viscosity of the oil in oil-n-water emulsions causes no appreciable increase in the viscosity of the emulsion.

The third method controlling the viscosity of the novel water-in-oil emulsions is by the use of secondary emulsicrs. It is preferred to control the viscosity of the novel water-in-oil emulsions by the use of base oils of greater or less viscosity and by regulation of the secondary emulsifier and the concentration thereof as discussed hereinbefore.

For example, the elect of the concentration of the secondary emulsier upon the viscosity of 1:1 water-inoil emulsion is well illustrated by the curve of the drawing. The base oil contained 94.5 weight per cent of 58/ 60 seconds S. U. V. 100 F. mineral oil, 1.5 weight per cent of one primary emulsier (aluminum stearate) and 4.0 weight per cent of a second primary emulsiiier (a fatty acid ester of a hexitol anhydride, the fatty acid of which has at least six carbon atoms'. to wit, Span 80). The concentration of the secondary emulsier; i. e., the oil-in-water emulsier (polyoxyalkylene derivative of a fatty acid ester of a hexitol anhydride in which the fatty acid has at least six carbon atoms; to wit, Tween 81) was varied between 0 and 4 weight per cent. As the graph illustrates, the viscosity varied between 400 and centipoise at 100 F. with the increase in concentration of the secondary emulsiier up to 2 weight per cent.

In View of the foregoing discussion, it is apparent that the present invention provides a soluble oil capable of dilution with up to about 69 Weight per cent water and comprising a major proportion of mineral oil of lubricating grade, a minor proportion of at least one material effective to inhibit wear and rust, a minor proportion of at least one material eiective to increase the film strength of the soluble oil, a minor proportion of at least one primary water-in-oil emulsiiier and suiiicient of at least one secondary oil-in-water emulsier to provide a soluble oil emulsion having the desired viscosity between about 100 and about 11,000 seconds, Saybolt Universal at 100 F.

It is to be understood that the specific anti-rust, antiwear, film-strength improvers, primary emulsiiiers and secondary emulsifiers specifically named herenbefore are only exemplary of the named classes of materials wellknown to those skilled in the art. Accordingly, the novel soluble oils are compounded in accordance with the followlng formulation:

Ingredient Weight Percent Prefelggelvteight One or more anti-wear and anti- 0.5 to 15.0. 6.0.

rust materials.1 One or more film-strength im- 0.25 to 5.0 3.0.

provers. One or more secondary emulsi- Up to 10 3.5.

fiers (oil-in-water). One or more primary emulsi- 0.5 to 10 2.0.

fiers (Water-in-oil). Mineral Oil (SUV. 40 to 900 Balance to make Balance to make 1 Anti-wear material and an anti-rust material can be substituted for material capable of performing both functions.

2 Sufficient secondary emulsifier is employed to produce the required viscosity.

We claim:

l. A soluble oil comprising: about 5 per cent by weight of neutral degras; about 1 per cent by weight of di(glycolmonooleate) malate; about 0.5 per cent by weight of oleyl acid phosphate; about 2.5 per cent by weight of chlorinated hydrocarbon having a chlorine content of 42 per cent by weight; and 1.5 per cent by weight of aluminum stearate; about 2 per cent by Weight of a fatty acid ester of a hexitol anhydride, said fatty acid having at least six carbon atoms; about 2 per cent by weight of a polyoxyalkylene derivative of a fatty acid ester of a hexitol anhydride, said fatty acid having at least six carbon atoms; and the balance, to make 100 per cent, mineral lubricating oil.

2. A soluble oil comprising: about 5 per cent by weight of neutral degras; about l per cent by weight of di(glycolmonooleate) malate; about 0.5 per cent by weight of oleyl acid phosphate; about 2.5 per cent by weight of chlorinated hydrocarbon having a chlorine content of 42 per cent by weight; about 1.5 per cent by weight of aluminum stearate; about 2 per cent by weight of sorbitan monooleate; a minor proportion of a polyoxyethylene sorbitan monooleate; and the balance, to make 100 per cent, mineral lubricating oil; said soluble oil containing an amount of said polyoxyethylene sorbitan monooleate which, when said soluble oil is diluted with water to provide an emulsion containing not more than about 69 per cent by Weight of water, is correlated with and eiective to produce a lubricant-coolant having a required viscosity.

3. The soluble oil defined by claim l wherein the lubricating oil is one having a Saybolt Universal Viscosity of 100 seconds at 100 F.

4. The soluble oil dened by claim 1 wherein the lubricating oil is one having a Saybolt Universal Viscosity of 60 seconds at 100 F.

Cil

Number Name Date Lebo Dec. 12, 1939 Kaufman Sept. l5, 1942 Wright Nov. 18, 1947 Fuller .Tune 15, 1948 Leland May 17, 1949 Francis et al. Ian. 3, 1950 OTHER REFERENCES Atlas Surface Active Agents, Atlas Power Co., p. l5,

copyright 1948. 

1. A SOLUBLE OIL COMPRISING: ABOUT 5 PER CENT BY WEIGHT OF NEUTRAL DEGRAS; ABOUT 1 PER CENT BY WEIGHT OF DI(GLYCOLMONOOLEATE) MALATE; ABOUT 0.5 PER CENT BY WEIGHT OF OLEYL ACID PHOSPHATE; ABOUT 2.5 PER CENT BY WEIGHT OF CHLORINATED HYDROCARBON HAVING A CHLORINE CONTENT OF 42 PER CENT BY WEIGHT; AND 1.5 PER CENT BY WEIGHT OF ALUMINUM STEARATE; ABOUT 2 PER CENT BY WEIGHT OF A FATTY ACID ESTER OF A HEXITOL ANHYDRIDE, SAID FATTY ACID HAVING AT LEAST SIX CARBON ATOMS; ABOUT 2 PER CENT BY WEIGHT OF A POLYOXYALKYLENE DERIVATIVE OF A FATTY ACID ESTER OF A HEXITOL ANHYDRIDE, SAID FATTY ACID HAVING AT LEAST SIX CARBON ATOMS; AND THE BALANCE, TO MAKE 100 PER CENT, MINERAL LUBRICATING OIL. 